(a) Field of the Invention
The present invention relates to a ball bearing sliding mechanism for drawers, particularly to a steel ball bearing type sliding drawer mechanism in which the sliding rail is movably connected to a retaining plate, such that the slits and the shoulder portion provided in the retaining plate are respectively retained with the protruded point and the stair portion of the blocking member, thereby preventing the drawers from falling off. The drawer can be pulled out and removed quickly by pressing the retaining plate, enhancing the alignment and the operation of the drawer.
(b) Description of the Prior Art
File cabinets with sliding drawers are used to store files and documents in the office. Since the files and documents are shared by a lot of users, the opening and closing of the drawers are quite frequent. Therefore, the smooth operation and the sturdiness of the sliding mechanism of the drawer relate to how well the files are organized in the drawer. In other words, if the sliding mechanisms of the drawer cannot be effectively aligned and sturdily suspended, then the drawer can be tipped over when it is extended, causing bodily injury or messing up the files. As shown in FIG. 1, the conventional ball bearing sliding mechanism mainly consists of a sliding rail (11), a retaining plate (13) and an intermediate rail (21). The sliding rail (11) is provided with a positioning holes (12). The retaining plate (13) is connected to one side of the sliding rail (11). The retaining plate (13), having an appropriate shape, consists of a holding rod (131). One side of the holding rod (131) has a resilient plate (132) connected thereof, and the other side of which is provided with a protruding retaining block (133). A securing hole (134) is provided in a suitable position of the retaining plate (134). The securing hole is also provided with rivet (135) for securing the retaining plate (13) through the positioning hole (12) to the sliding rail (11). The intermediate rail (21), having an appropriate shape, is provided with a holding block (22). The holding block (22) is provided with a protruded block (23) in a suitable position such that when the sliding rail (11) slides out, the protruded block (23) is retained with the retaining block (133) of the retaining plate (13).
The above configuration of the conventional sliding drawer mechanism is capable to interlock the sliding rail (11), however, there are some drawbacks in the operation:
1. When the sliding rail (11) is engaged with the intermediate rail (21), as is shown in FIG. 2A, the edge of the retaining block (133) of the retaining plate (13) comes in contact with the protruded block (23) of the intermediate rail (21). Therefore, when the retaining plate (13) is pushed forward, the protruded block (23) of the intermediate rail (21) presses onto the retaining block (133) of the retaining plate (13), thereby deforming the resilient plate (132) of the retaining plate (13). This forces the retaining plate (13) to pass underneath the protruded block (23) so that the sliding rail (11) slides into the intermediate rail (21). Hence, under a prolonged operation, the pressing from the top edge of the protruded block (23) onto the side of the retaining block (133) can cause wears and tears on the protruded block (23) or the retaining block (133). Therefore, the component of the retaining plate can be damaged for extended operation and this is definitely one of the drawbacks of this structure.
2. When the sliding rail (11) needs to be pulled out, as is shown in FIG. 2B, the retaining plate (13) is retained with the protruded block (23) of the intermediate rail (21), therefore, the holding rod (131) of the retaining plate (13) has to be pushed downward, thereby allowing the retaining block (133) of the retaining plate (13) to displace downward and disengage from the protruded block (23). However, the retaining block (133) is not moving downward in a lateral direction, instead, it slides downward in a path of an arc. Hence, the frequent usage of the device causes the retaining block (133) or the protruded block (23) to wear out. In addition, the top of the retaining block (133) can also be worn out to have a circular arc shape, making it fails to retain with the protruded block (23) and affecting the alignment of the drawer. This inconvenience in operation is the second disadvantage of the conventional sliding mechanism.
3. The conventional sling drawer sliding mechanism provides an interlocking of the retaining plate (13) and the protruded block (23) of the intermediate rail. This is only a one-way interlocking to prevent the drawer to slide out by itself. It cannot hold the drawer in place. Any touching on the drawer can cause it to slide towards the inner side, causing a lot of inconveniences in operation. This is the third disadvantage.
The Inventor, with many years of experience in the manufacturing and design of such product, has come up with an improved structure for the drawer sliding mechanism which is simple and convenient to use, easy to operate and gives a perfect interlocking.